<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        const arr = [10, 20, 30]
        // arr.forEach(function(el. i){
        //     console.log(el)
        // })

        // 箭头函数写法
        arr.forEach(el => console.log(el))

        // 
        const newArr = arr.map(i => i + 6)
        console.log(newArr)
    </script>
</body>
</html>